Lisa Robin Kelly, the trouble former
"That '70s Show" star, passed away on Wednesday (Aug. 14) at the age of 43.

TMZ reports that the actress, who portrayed Eric Forman's (
Topher Grace) older sister on the long-running FOX comedy, died in her sleep on Wednesday night while at a rehab facility in California. Her agent tells the website Kelly had voluntarily checked herself in for treatment just this past week, determined to find sobriety.

"She had been fighting demons for a while and finally lost her battle," the agent says.

Kelly had
several run-ins with the law over the past few years, finding herself arrested at least four times since 2010 for charges ranging from DUI to
assault and
spousal abuse. She filed for divorce from husband Robert Gilliam in July, hoping to put an end to a marriage crippled by allegations of abuse by both parties.

Our thoughts remain with Kelly's family and friends during this time of loss.